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4,310 interview questions, answered.

Reference answers, what the interviewer is really testing, how it is graded, and the follow-ups that come next.

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1,063 questions

  1. 841Merge k sorted linked lists.HardCoding· Adobe, Apple
  2. 842Find the minimum characters to insert to make a string a palindrome.MediumCoding· Uber
  3. 843Given a large n-ary tree where the root node can pass information to one child per iteration, and in subsequent iterations, nodes can pass information to one child while the root continues with others, find the minimum number of iterations to reach all nodes.MediumCoding· Google
  4. 844Given two strings (Word 1 and Word 2) and a list of valid words from a dictionary, return the minimum number of operations required to convert Word 1 to Word 2.HardCoding· Airbnb
  5. 845Find the minimum window substring.MediumCoding· Airbnb, Dropbox
  6. 846Most Common WordsEasyCoding· Amazon
  7. 847Move all zeros to the end of an array.EasyCoding· Adobe, Amazon
  8. 848Given a string of parentheses types and an array of their efficiency ratings, write a function to find the most efficient valid parentheses sequence that can be formed. Return its total efficiency score.HardCoding· Amazon
  9. 849Partition an array into two sub-arrays with equal sum.MediumCoding· Apple, LinkedIn
  10. 850Print all words from a dictionary that can be found on a given Boggle board.MediumCoding· Microsoft
  11. 851Given a matrix with a rat, bread, cat, and obstacles, find a path from the rat to the bread that maximizes the minimum distance from cat.HardCoding· Google
  12. 852Write functions to serialize and deserialize a list of strings.MediumCoding· Google, Nvidia
  13. 853Session Data Analysis.HardCodingTechnical· Amazon
  14. 854Sort an array containing only 0s, 1s, and 2s.MediumCodingTechnical· LinkedIn
  15. 855Sort a binary array in linear time.EasyCoding· Accenture, Apple
  16. 856How do you split a machine learning dataset for training, evaluation, and testing?MediumCoding· Amazon
  17. 857Write a query to find all dates where the stadium had three or more consecutive days with attendance of 100 or more people.HardCodingData· Amazon
  18. 858Write a query to find the top 3 unique salaries in each department and list all employees who have those salaries.MediumCodingData· Amazon
  19. 859Squares of sorted arrayMediumCoding· Meta, PayPal
  20. 860Given a sorted array of integers (which may include negatives), return the squares of the numbers in sorted order. As a follow-up, find the k-th smallest squared value.MediumCoding· Uber
  21. 861How would you store a list of numbers as a single number?MediumCodingTechnical· Atlassian, Microsoft
  22. 862Given an integer array nums and an integer k, return true if nums has a subarray of at least two elements whose sum is a multiple of k.HardCoding· Adobe, Apple
  23. 863Sudoku SolverHardCoding· Adobe, Apple
  24. 864Get the top API users based on transaction logs.MediumCoding· Amazon